I'm a mother of smaller children who has recently had to hire a baby sitter now and again so my dh and I can have some "us" time. I babysat as a teen (older teen) and have never had poor treatment or non-payment -- that was many, many, many years ago.
For Saturday, the teen said her parents could drop her off or pick her up. That isn't necessary, but I told her if they wanted to that was fine. They would probably like to see where she is going. If it is a non-driving teen, I've picked up and drove them home. I had a young teen driver and I made sure we were home before the cut off time for her to drive home and I called her home before she left so they knew to expect her soon.
As for payment, if I pick up at 4:30pm and leave the house at 5pm, I still pay the sitter for the 30 minutes. And if the $ amount ends up odd, I round up -- mostly b/c I can and I want to. The girls don't ask for much around here, $2 per hour per child in multiple child homes).
For example: We went to an all day marriage conference a few months ago. I picked up at 7:15am and we were home at 3:45pm, she was dropped off at 4pm. I based the pay on 9 hours at $6 which was not really even, I paid her $60. I think that is being nice and I liked her, she knew something about food allergies which is a help w/ my Celiac son. I'd like her to feel that she could sit for me again. I also know she is earning money for a missions trip with our church this summer, so why not help her out if I can. She'll be sitting for me again this Sat.
I use sitters so infrequently that the girl I used the 1st time was not baby sitting a year later b/c she had a job. The 2nd girl I hired was not mature enough for me, this young girl was just turned 14 and the youngest in the family. She also didn't follow the instructions I left. She put my kids to bed at 7pm about an hour after we left! I left instructions not to put them in their PJs until 8:30pm and that when we got home around 9:30pm I'd put them in bed. They screamed for a while and then she took the youngest out of the crib. And now I'm using girl #3 and she is younger than I like, age 14, but definitely more mature than #2.
When I babysat I was 15, 16, 17, 18 and 19 -- there were no other jobs for teens. I grew up overseas. When I was 11 & 12 the neighbor wanted some extra help in the house, so I would come over after school and entertain her 2 girls and get paid some. I don't recall what the mother was doing. It was nice b/c I got to experience taking care of kids with an adult near by. Of course, I remember at age 18 calling my mother up and asking her what I should do!
(Parents were late and older baby was screaming, hitting my chest and her 3 yr old twin brothers said she didn't drink from a bottle. I could do nothing for her, it was horrible. I found a bottle and didn't know if I should give the poor girl some water or not.) So I try to remember that and give good instructions and notes b/c nothing is worse than having a screaming baby that isn't yours!!! And every situation is different and what worked for the neighbor's children, may not work for the couple down the street.
The sitter my mother used when we were kids was 16 or 17 and then her brother at 16 and 17. I honestly do not like leaving my children, especially babies under 2 in the care of young teens (13 and 14 and some 15 yr olds). But as one mother of a teen told me, as soon as they can get a real job they do b/c it pays better. But I've found some teens are more able to handle the responsibility than others, unfortunately you can't always know that even if you ask the parent until you try the young person out.
Anyway, I am sorry your dd is being 'abused' by those hiring her. I think I would call the parents, but then again I might want to teach my dd to stand up for herself polietly. I think it will depend on my dd and the severity of the situation. I would definitely place a phone call to the family who let her walk home at 11pm by herself -- that is just wrong. Did they call you so you could step outside and look for her? If it was a few houses, I would not mind if I knew she was coming and I could step out to the curb and watch her from their driveway to mine. If there are any blind spots on the trip, that is not acceptable, nice neighborhood or not -- it's dangerous, it only takes a couple of seconds to loose your child forever to a preditor.